Support "Webhook"

[quyendang]

I would like you to add a webhook integration feature that allows miner information to be sent periodically to a server, enabling users to monitor their Bitaxe miner remotely.

Please add an “Enable Webhook” option in the Settings section. When the webhook is enabled, users should be able to enter:

• The Webhook URL
• The interval between each miner status update

After a reset, the ESP32 should periodically send miner information to the webhook server using the HTTP POST method according to the configured interval.

[vortexopenclaw]

This would be great to add in the same functionality we have with the NerdQAxe series.

It could give us Discord alerts for things like block found or new best difficulty achieved.

I saw you have a PR #1523 which has been superseded by #1623, but those are not for pushing Webhook alerts elsewhere in to places like Discord.